Brother Jonathan

When Washington was in want of ammunition, he called a council
of officers, but no practical suggestion could be offered. “We must
consult brother Jonathan,” said the general, meaning his excellency,
Jonathan Trumbull, the elder governor of the State of Connecticut. This
was done, and the difficulty was remedied. To consult brother Jonathan
then became a set phrase, and brother Jonathan grew to be the John Bull
of the United States. (J. R. Bartlett: Dictionary of Americanisms.)